The present invention relates to a new and improved construction of apparatus for counting printed products arriving upon a conveyor path or track in an imbricated product stream, which apparatus is of the type comprising a feeler which bears under the action of a contact force upon the imbricated product stream and is secured against entrainment in the conveying direction of the product stream, this feeler cooperating with an electrical signal transmitter. The invention also is directed to a method of operating the apparatus for counting such printed products.
According to a state-of-the-art apparatus of this type, as disclosed for instance in Swiss Pat. No. 382,477, the feeler is coupled with a tab, and during throughpassage of a printed product the feeler and thus the tab are deflected, so that a light barrier is interrupted which, in turn, delivers the signal required for counting purposes. This construction is useful as long as the thickness of the printed products which are to be counted does not fall below a minumum value, and furthermore, is maintained only within relatively narrow limits. Additionally, the counting speed of the prior art apparatus is no longer capable of coping in all instances with the production capacity of modern high speed rotary printing presses. This should be readily evident if it is realized that the tab which interrupts the light barrier in the case of a deflection brought about only by the thickness of one or two sheets of paper is not capable of positively interrupting the light barrier and, moreover, the tab, following each interruption of the light barrier, must again free such light barrier. Furthermore, in the case of very thick product copies there must be resorted to special measures in order to limit the deflection of the tab or the like.